lisp/mouse-copy.el

   1 ;;; mouse-copy.el --- one-click text copy and move
   2
   3 ;; Copyright (C) 1996 Free Software Foundation, Inc.
   4
   5 ;; Author: John Heidemann <johnh@ISI.EDU>
   6 ;; Keywords: mouse
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;;; What is ``mouse-copy.el''?
  28 ;;;
  29 ;;; It provides one-click text copy and move.  Rather than the
  30 ;;; standard stroke-out-a-region (down-mouse-1, up-mouse-1) followed
  31 ;;; by a yank (down-mouse-2, up-mouse-2 or C-y), you can now stroke
  32 ;;; out a region and have it automatically pasted at the current
  33 ;;; point.  You can also move text just as easily.  Although the
  34 ;;; difference may not sound like much, it does make mousing text
  35 ;;; around a lot easier, IMHO.
  36 ;;;
  37 ;;; If you like mouse-copy, you should also check out mouse-drag
  38 ;;; for ``one-click scrolling''.
  39 ;;;
  40 ;;; To use mouse-copy, place the following in your .emacs file:
  41 ;;;     (require 'mouse-copy)
  42 ;;;     (global-set-key [M-down-mouse-1] 'mouse-drag-secondary-pasting)
  43 ;;;     (global-set-key [M-S-down-mouse-1] 'mouse-drag-secondary-moving)
  44 ;;;
  45 ;;; (These definitions override the old binding of M-mouse-1 to
  46 ;;; mouse-drag-secondary.  I find I don't use that command much so its
  47 ;;; loss is not important, and it can be made up with a M-mouse-1
  48 ;;; followed by a M-mouse-3.  I personally reserve M-mouse bindings
  49 ;;; for my window manager and bind everything to C-mouse.)
  50 ;;;
  51 ;;;
  52 ;;; History and related work:
  53 ;;;
  54 ;;; One-click copying and moving was inspired by lemacs-19.8.
  55 ;;; Throw-scrolling was inspired by MacPaint's ``hand'' and by Tk's
  56 ;;; mouse-2 scrolling.  The package mouse-scroll.el by Tom Wurgler
  57 ;;; <twurgler@goodyear.com> is similar to mouse-drag-throw, but
  58 ;;; doesn't pass clicks through.
  59 ;;;
  60 ;;; These functions have been tested in emacs version 19.30,
  61 ;;; and this package has run in the past on 19.25-19.29.
  62 ;;;
  63 ;;; Originally mouse-copy was part of a larger package.
  64 ;;; As of 11 July 96 the scrolling functions were split out
  65 ;;; in preparation for incorporation into (the future) emacs-19.32.
  66 ;;;
  67 ;;;
  68 ;;; Known Bugs:
  69 ;;;
  70 ;;; - Highlighting is sub-optimal under 19.29 and XFree86-3.1.1
  71 ;;;   (see \\[mouse-copy-work-around-drag-bug] for details).
  72 ;;; - mouse-drag-secondary-pasting and mouse-drag-secondary-moving
  73 ;;;   require X11R5 (or better) and so fail under older versions
  74 ;;;   of Open Windows (like that present in Solaris/x86 2.1).
  75 ;;;
  76 ;;;
  77 ;;; Future plans:
  78 ;;;
  79 ;;; I read about the chording features of Plan-9's Acme environment at
  80 ;;; <http://www.zip.com.au/~cs/app/wily/auug.html>.  I'd like
  81 ;;; to incorporate some of these ideas into mouse-copy.  The only
  82 ;;; lose is that this is not the current Emacs Way Of Doing Things, so
  83 ;;; there would be a learning curve for existing emacs users.
  84 ;;;
  85 ;;;
  86 ;;; Thanks:
  87 ;;;
  88 ;;; Thanks to Kai Grossjohann
  89 ;;; <grossjoh@dusty.informatik.uni-dortmund.de> for reporting bugs, to
  90 ;;; Tom Wurgler <twurgler@goodyear.com> for reporting bugs and
  91 ;;; suggesting fixes, and to Joel Graber <jgraber@ti.com> for
  92 ;;; prompting me to do drag-scrolling and for an initial
  93 ;;; implementation of horizontal drag-scrolling.
  94 ;;;
  95 ;;;    -johnh, 11-Jul-96
  96 \f
  97 ;;; Code:
  98
  99 ;;
 100 ;; move/paste code
 101 ;;
 102
 103 (defvar mouse-copy-last-paste-start nil
 104   "Internal to `mouse-drag-secondary-pasting'.")
 105 (defvar mouse-copy-last-paste-end nil
 106   "Internal to `mouse-drag-secondary-pasting'.")
 107
 108 (defvar mouse-copy-have-drag-bug nil
 109   "Set to enable mouse-copy-work-around-drag-bug.
 110 See `mouse-copy-work-around-drag-bug' for details.")
 111
 112 (defun mouse-copy-work-around-drag-bug (start-event end-event)
 113   "Code to work around a bug in post-19.29 emacs:  it drops mouse-drag events.
 114 The problem occurs under XFree86-3.1.1 (X11R6pl11) but not under X11R5,
 115 and under post-19.29 but not early versions of emacs.
 116
 117 19.29 and 19.30 seems to drop mouse drag events
 118 sometimes. (Reproducible under XFree86-3.1.1 (X11R6pl11) and
 119 XFree86-3.1.2 under Linux 1.2.x.  Doesn't occur under X11R5 and SunOS
 120 4.1.1.)
 121
 122 To see if you have the problem:
 123 Disable this routine (with (setq mouse-copy-have-drag-bug nil)).
 124 Click and drag for a while.
 125 If highlighting stops tracking, you have the bug.
 126 If you have the bug (or the real fix :-), please let me know."
 127
 128   ;; To work-around, call mouse-set-secondary with a fake
 129   ;; drag event to set the overlay,
 130   ;; the load the x-selection.
 131   (save-excursion
 132     (let*
 133         ((start-posn (event-start start-event))
 134          (end-posn (event-end end-event))
 135          (end-buffer (window-buffer (posn-window end-posn)))
 136          ;; First, figure out the region (left as point/mark).
 137          (range (progn
 138                   (set-buffer end-buffer)
 139                   (mouse-start-end (posn-point start-posn)
 140                                  (posn-point end-posn)
 141                                  (1- (event-click-count start-event)))))
 142          (beg (car range))
 143          (end (car (cdr range))))
 144       ;; Second, set the overlay.
 145       (if mouse-secondary-overlay
 146           (move-overlay mouse-secondary-overlay beg end)
 147         (setq mouse-secondary-overlay (make-overlay beg (posn-point end))))
 148       (overlay-put mouse-secondary-overlay 'face 'secondary-selection)
 149       ;; Third, set the selection.
 150       ;; (setq me-beg beg me-end end me-range range)  ; for debugging
 151       (set-buffer end-buffer)
 152       (x-set-selection 'SECONDARY (buffer-substring beg end)))))
 153
 154
 155 (defun mouse-drag-secondary-pasting (start-event)
 156   "Drag out a secondary selection, then paste it at the current point.
 157
 158 To test this function, evaluate:
 159         (global-set-key [M-down-mouse-1] 'mouse-drag-secondary-pasting)
 160 put the point at one place, then click and drag over some other region."
 161   (interactive "e")
 162   ;; Work-around: We see and react to each part of a multi-click event
 163   ;; as it proceeds.  For a triple-event, this means the double-event
 164   ;; has already copied something that the triple-event will re-copy
 165   ;; (a Bad Thing).  We therefore undo the prior insertion if we're on
 166   ;; a multiple event.
 167   (if (and mouse-copy-last-paste-start
 168            (>= (event-click-count start-event) 2))
 169       (delete-region mouse-copy-last-paste-start
 170                      mouse-copy-last-paste-end))
 171
 172   ;; HACK: We assume that mouse-drag-secondary returns nil if
 173   ;; there's no secondary selection.  This assumption holds as of
 174   ;; emacs-19.22 but is not documented.  It's not clear that there's
 175   ;; any other way to get this information.
 176   (if (mouse-drag-secondary start-event)
 177       (progn
 178         (if mouse-copy-have-drag-bug
 179             (mouse-copy-work-around-drag-bug start-event last-input-event))
 180         ;; Remember what we do so we can undo it, if necessary.
 181         (setq mouse-copy-last-paste-start (point))
 182         (insert (x-get-selection 'SECONDARY))
 183         (setq mouse-copy-last-paste-end (point)))
 184     (setq mouse-copy-last-paste-start nil)))
 185
 186
 187 (defun mouse-kill-preserving-secondary ()
 188   "Kill the text in the secondary selection, but leave the selection set.
 189
 190 This command is like \\[mouse-kill-secondary] (that is, the secondary
 191 selection is deleted and placed in the kill ring), except that it also
 192 leaves the secondary buffer active on exit.
 193
 194 This command was derived from mouse-kill-secondary in emacs-19.28
 195 by johnh@ficus.cs.ucla.edu."
 196   (interactive)
 197   (let* ((keys (this-command-keys))
 198          (click (elt keys (1- (length keys)))))
 199     (or (eq (overlay-buffer mouse-secondary-overlay)
 200             (if (listp click)
 201                 (window-buffer (posn-window (event-start click)))
 202               (current-buffer)))
 203         (error "Select or click on the buffer where the secondary selection is")))
 204   (save-excursion
 205     (set-buffer (overlay-buffer mouse-secondary-overlay))
 206     (kill-region (overlay-start mouse-secondary-overlay)
 207                  (overlay-end mouse-secondary-overlay)))
 208   ;; (delete-overlay mouse-secondary-overlay)
 209   ;; (x-set-selection 'SECONDARY nil)
 210   ;; (setq mouse-secondary-overlay nil)
 211 )
 212
 213 (defun mouse-drag-secondary-moving (start-event)
 214   "Sweep out a secondary selection, then move it to the current point."
 215   (interactive "e")
 216   ;; HACK:  We assume that mouse-drag-secondary returns nil if
 217   ;; there's no secondary selection.  This works as of emacs-19.22.
 218   ;; It's not clear that there's any other way to get this information.
 219   (if (mouse-drag-secondary start-event)
 220       (progn
 221         (mouse-kill-preserving-secondary)
 222         (insert (x-get-selection 'SECONDARY))))
 223 )
 224
 225 (provide 'mouse-copy)
 226
 227 ;;; mouse-copy.el ends here